Avoidance

♠

A

9

8

7

♥

♦

A

♣

♠

K

2

♠

Q

5

♥

A

Q

3

♥

9

8

7

♦

♦

♣

♣

♠

6

4

♥

K

2

♦

2

♣

Contract is NT.  South to lead.  Win 3 tricks.

Solution:  As per the the title this is all about avoidance; you cannot allow East on lead.  You need to start by leading a low spade.  If West plays the king you duck it, if West plays low you win it with the ace and play a second low spade, forcing West to win with the king.  Either way after winning the spade king West will be able to take a second trick with the ace of hearts but North's spades will be good and you have the ace of diamonds as an entry.